Generally speaking, catheters are widely used medical devices. Catheters are used intravascularly, intraperitoneally and to provide drainage or treatment for body cavities. Catheters used intravascularly and intraperitoneally are often left in place for extended periods of time with multiple attachments and detachments of fluid handling devices for administration of fluids. With the advent of managed care, many procedures formerly performed only in clinical settings by skilled practitioners are now being practiced by less skilled, although highly motivated, family members or by the patients themselves in non-clinical locations. Intraperitoneal dialysis is one example of such a procedure. In an intraperitoneal dialysis procedure, a patient has many liters of dialysis fluid introduced into the peritoneal cavity for a residence period. The residence period enables the fluid to acquire materials that would normally be excreted by the kidney. After the residence period the dialysis fluid is withdrawn from the patient's peritoneal cavity. Since the fluid is directly introduced into the patient, and the process is repeated almost daily, if there are any microorganisms transmitted along with the fluid, there is a risk of the patient developing a life threatening infection. Prevention of infection in such procedures is primary concern of practitioners involved in this type of practice.
In many chemotherapy procedures, a patient is infused with materials that are potentially toxic to the person administering the treatment. In such cases, prevention of spills during connection and disconnection of the fluid handling device is important. Prevention of spills is also an important consideration in the administration of radioactive pharmaceuticals. Microbial contamination of fluid handling connections to catheters used for total parental nutrition presents risk to patients already in a weakened state.
There have been many studies of the mechanism of infection with catheters used in many of these treatments. One finding of these studies is that a common source of contaminating microorganisms is finger contact with the connectors. Protocols for attachment and detachment of fluid handling devices to catheters often dictate the practitioner's use of rubber gloves, require wiping the connector's surface clean and other sterile practices. These protocols are often difficult to adhere to even for skilled personnel in clincal settings. When treatments involving the use of catheters is moved to an ambulatory and out-patient setting, the adherence to elaborate infection control protocols becomes even more difficult. As a result of these difficulties, there has been considerable effort to develop connectors for attaching fluid handling devices to catheters that are less prone to contamination.
Another area of infection prevention is development of connectors that are antimicrobial. U.S. Pat. No. 5,536,258 to Folden discloses an antimicrobial tubing connector for medical procedures. The '258 patent teaches that about sixty percent of the continuous ambulatory peritoneal dialysis (CAPD) patients develop peritonitis within two years after starting the treatment. The '258 patent further teaches that there are many protocols and types of connectors that have been developed to address the problem of contamination of connectors used for repeated connections and disconnections of medical fluid transfer procedures. The solution to the connector contamination problem disclosed in the '258 patent is a connector with a recessed male portion and a female portion with "O" rings that form a seal around the recessed male portion. The '258 patent further teaches that an antimicrobial silver coating is applied to one or more of the surfaces of the connector. While the '258 patent recognizes the contamination problems associated with medical connectors, the device disclosed therein still presents exposed mating surfaces when the male portion is disconnected from the female portion.
Another patent, U.S. Pat. No. 5,582,600, to Loh discloses a connector assembly that has a key component and a lid lock component to provide fluid communication between a fluid source and a destination such as a patient. While the teachings of this patent again recognize the contamination problems associated with repeated connections and disconnections of fluid transmission devices to patients, only one side of one part of the disclosed connector is covered when the parts of the connector are disconnected from each other.
Contamination of exposed connectors used with infusion devices when the parts of the connectors are not attached to each other is a present and ongoing problem, particularly for patients that have compromised immune systems. Although the patents listed above have recognized and identified many of the problems of contamination of catheter connectors, the disclosures of these patents do not address the need for a connector for medical fluid transfers that has a valve in each portion of the connector and that substantially prevents exposure of the fluid contact surfaces when the portions of the connector are disconnected. Such a connector is disclosed hereinbelow.